Superhydrophobicity in nature is the result of multiscale (hierarchical) roughness which consists of nano-asperities superimposed on micrometer scale roughness. A low-cost superhydrophobic surface was prepared by depositing soot on Vaseline coated glass substrates. The surface was rapidly prepared without any sophisticated fabrication facilities. The surface exhibited a remarkably high water contact angle of 161 deg and a roll-off angle of 3 deg. Atomic force microscopy (AFM) of the surface was done which revealed a very rough surface. The roughness features with nano-asperities superimposed on micrometer scale roughness enhance the water repellency. The micrometer scale peaks on the surface support the water droplet in a Cassie–Baxter state with the nano-asperities sheltering a composite interface below the droplet. The work of adhesion for the surface was also low at 18 nJ. The study will enable easy preparation of a cost effective superhydrophobic surface.

References

References
1.
Roach
,
P.
,
Shirtcliffe
,
N. J.
, and
Newton
,
M. I.
,
2008
, “
Progress in Superhydrophobic Surface Development
,”
Soft Matter
,
4
(
2
), pp.
224
240
.10.1039/b712575p
2.
Shirtcliffe
,
N. J.
,
McHale
,
G.
,
Atherton
,
S.
, and
Newton
,
M. I.
,
2010
, “
An Introduction to Superhydrophobicity
,”
Adv. Colloid Interface Sci.
,
161
(
1–2
), pp.
124
138
.10.1016/j.cis.2009.11.001
3.
Quéré
,
D.
,
2008
, “
Wetting and Roughness
,”
Annu. Rev. Mater. Res.
,
38
(
1
), pp.
71
99
.10.1146/annurev.matsci.38.060407.132434
4.
Guo
,
Z.
,
Liu
,
W.
, and
Su
,
B. L.
,
2011
, “
Superhydrophobic Surfaces: From Natural to Biomimetic to Functional
,”
J. Colloid Interface Sci.
,
353
(
2
), pp.
335
355
.10.1016/j.jcis.2010.08.047
5.
Callies
,
M.
, and
Quéré
,
D.
,
2005
, “
On Water Repellency
,”
Soft Matter
,
1
(
1
), pp.
55
61
.10.1039/b501657f
6.
Zhang
,
X.
,
Shi
,
F.
,
Niu
,
J.
,
Jiang
Y.
, and
Wang
,
Z.
,
2008
, “
Superhydrophobic Surfaces: From Structural Control to Functional Application
,”
J. Mater. Chem.
,
18
(
6
), pp.
621
633
.10.1039/b711226b
7.
Courbin
,
L.
,
Bird
,
J. C.
,
Belmonte
,
A.
, and
Stone
,
H. A.
,
2008
, “
“Black Hole” Nucleation in a Splash of Milk
,”
Phys. Fluids
,
20
, p.
091106
.10.1063/1.2973667
8.
Bocquet
,
L.
, and
Lauga
,
E.
,
2011
, “
A Smooth Future?
,”
Nat. Mater.
,
10
(
5
), pp.
334
337
.10.1038/nmat2994
9.
Qu
,
M.
,
He
,
J.
, and
Cao
,
B.
,
2010
, “
Facile Fabrication of Large-Scale Stable Superhydrophobic Surfaces With Carbon Sphere Films by Burning Rapeseed Oil
,”
Appl. Surf. Sci.
,
257
(
1
), pp.
6
9
.10.1016/j.apsusc.2010.05.011
10.
Yuan
,
L.
,
Dai
,
J.
,
Fan
,
X.
,
Song
,
T.
,
Tao
,
Y. T.
,
Wang
,
K.
,
Xu
,
Z.
,
Zhang
,
J.
,
Bai
,
X.
,
Lu
,
P.
,
Chen
,
J.
,
Zhou
,
J.
, and
Wang
,
Z. L.
,
2011
, “
Self-Cleaning Flexible Infrared Nanosensor Based on Carbon Nanoparticles
,”
ACS Nano
,
5
(
5
), pp.
4007
4013
.10.1021/nn200571q
11.
12.
Stalder
,
A. F.
,
Kulik
,
G.
,
Sage
,
D.
,
Barbieri
,
L.
, and
Hoffmann
,
P.
,
2006
, “
A Snake-Based Approach to Accurate Determination of Both Contact Points and Contact Angles
,”
Colloids Surf., A
,
286
(
1–3
), pp.
92
103
.10.1016/j.colsurfa.2006.03.008
13.
gwyddion
,
2011
, http://gwyddion.net/
14.
Berthier
,
J.
,
2008
,
Microdrops and Digital Microfluidics
,
William Andrew
,
Norwich, NY
, Chap. 2.
15.
Yoon
,
J. Y.
,
2008
, “
Open Surface Digital Microfluidics
,”
Open Biotechnol. J.
,
2
, pp.
94
100
.10.2174/1874070700802010094
16.
Mitra
,
A.
,
2000
,
Fundamentals of Quality Control and Improvement
,
Prentice-Hall
,
New Jersey
, Chap. 3.
17.
Nosonovsky
,
M.
,
2007
, “
Multiscale Roughness and Stability of Superhydrophobic Biomimetic Interfaces
,”
Langmuir
,
23
(
6
), pp.
3157
3161
.10.1021/la062301d
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